Either d1$a and d2$a are always the same, or they are not.
If they are already the same, you can either omit one of them in the merge:
merge(d1, d2[,-2], by="b")
or you can use a set of columns for your by:
merge(d1,d2, by=c("a","b"))
If the "a" columns are distinct, then at least one of them needs a new name in
the merged table, and the simplest option is to rename the columns
appropriately in d1 and d2 (since they apparently represent different data
anyway).
---------------------------------------------------------------------------
Jeff Newmiller The ..... ..... Go Live...
DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go...
Live: OO#.. Dead: OO#.. Playing
Research Engineer (Solar/Batteries O.O#. #.O#. with
/Software/Embedded Controllers) .OO#. .OO#. rocks...1k
---------------------------------------------------------------------------
Sent from my phone. Please excuse my brevity.
jpm miao <miao...@gmail.com> wrote:
>Hi,
>
> From time to time I merge two dataframes with possibly a common field.
>Then the common field is no longer present,but what are present
>fieldname.x
>and fieldname.y. How can I fix the problem so that I can still call by
>the
>orignal fieldname? If you don't understand my problem, please see the
>example below.
>
> Thanks
>
>Miao
>
>
>> d1
> a b c
>1 1 4 5
>2 2 5 6
>3 3 6 7
>> d2
> d a f b
>1 6 1 8 4
>2 7 2 9 5
>3 8 3 10 6
>> d3<-merge(d1, d2, by="b")
>> d3
> b a.x c d a.y f
>1 4 1 5 6 1 8
>2 5 2 6 7 2 9
>3 6 3 7 8 3 10
>> d3["a"]
>Error in `[.data.frame`(d3, "a") : undefined columns selected
>> d3["a.x"]
> a.x
>1 1
>2 2
>3 3
>
> [[alternative HTML version deleted]]
>
>______________________________________________
>R-help@r-project.org mailing list
>https://stat.ethz.ch/mailman/listinfo/r-help
>PLEASE do read the posting guide
>http://www.R-project.org/posting-guide.html
>and provide commented, minimal, self-contained, reproducible code.
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
